The Flood of the Arno River causes massive damage in Florence, Italy, 1333Joan of Arc liberates Saint-Pierre-le-Moûtier, 1429Thomas Wolsey, English cardinal, arrested, 1529Mozart's Symphony No. 36 is performed for the first time in Linz, Austria, 1783The Erie Canal is completed with Governor DeWitt Clinton performing the Wedding of The Waters ceremony in New York Harbour, 1825Benjamin Palmer patents an artificial leg, 1846Dentist John Beers of San Francisco patents the gold crown, 1873Tonga adopts a constitution, 1875James Ritty patents the cash register, to combat the pilfering of the till by the bartenders in his Ohio saloon, 1879London's first deep-level tube railway opens between King William Street and Stockwell, 1890The Italian unknown soldier is buried in the Altare della Patria (Fatherland Altar) in Rome, 1921Nellie Tayloe Ross is elected the first female US State governor, in Wyoming, 1924The rebuilt Vienna State Opera reopens with a performance of Beethoven's Fidelio, 1955Two-thirds of Florence, Italy is submerged as the River Arno floods; together with the contemporaneous flood of the Po River in northern Italy, this leads to 113 deaths, 30,000 made homeless, and the destruction of numerous Renaissance artworks and books, 1966Genie, a 13-year-old feral child is found in Los Angeles, California having been locked in her bedroom for most of her life, 1970The Netherlands experiences the first Car Free Sunday caused by the oil crisis, as the highways are deserted and are used only by cyclists and roller skaters, 1973First conference that focuses exclusively on the subject of the commercial potential of the World Wide Web, in San Francisco, 1994Israeli prime minister Yitzhak Rabin is assassinated by an extremist Orthodox Israeli, 1995Chinese authorities arrest cyber-dissident He Depu for signing a pro-democracy letter to the 16th Communist Party Congress, 2002Barak Obama is elected President of the United States, 2008